1. Field of the Invention
This invention generally relates to primers and more particularly to a lead and barium free priming composition for use in ammunition.
2. Description of the Related Art
Various lead free priming mixtures for use in ammunition have been disclosed over the years. For example, my nontoxic, noncorrosive priming mix described in U.S. Pat. No. 4,675,059 is one such composition. This priming composition is specifically adapted to rim fire cartridges and contains diazodinitrophenol, also known as dinol or DDNP, manganese dioxide, tetrazene and glass.
Another example of a nontoxic priming mixture is U.S. Pat. No. 4,963,201, issued to Bjerke et al. This composition comprises dinol or potassium dinitrobenzofuroxane as the primary explosive, tetrazene as a secondary explosive, a nitrate ester fuel and strontium nitrate as the oxidizer.
Other examples are disclosed in U.S. Pat. Nos. 4,363679 and 4,581,082, issued to Hagel et al. In these patents, the initiating explosive may be strontium salts of mono- and dinitrodihydroxydiazobenzenes, and metal-free compounds such as diazodinitrophenol, tetrazene, or nitrogen tetrasulfide. Zinc peroxide is utilized as the sole or predominant oxidant. Zinc peroxide is a powerful oxidizer. However, it is an inefficient one. Only one oxygen atom per molecule is available for oxidation reactions. It is also difficult to get zinc peroxide in pure form. The result is reduced gas output and a cool flame with high slag content in the combustion product.
Another nontoxic primer mix is disclosed in U.S. Pat. No. 4,608,102 to Krampen. This mix has manganese dioxide as an oxidizer with dinol. The manganese dioxide, like zinc dioxide, is a powerful oxidizer but is inefficient and has the same drawbacks as the mix in Hagel et al.
These nontoxic mixes are less sensitive than the lead styphnate compositions. Therefore the metal parts configuration of the primer must be carefully optimized to ensure reliable ignition. This can only be done consistently in the Betdan primer system where the primer anvil is part of the cartridge and the primer factory installed under rigorously controlled conditions. Thus these nontoxic mixes are preferably used in Berdan type primers. Cartridges which use Bardan primers are not reloadable as the anvil is an integral part of the cartridge case. Also, the primer case is not readily removable and the primer cavity cannot adequately be cleaned after use.
Boxer type primers, on the other hand, contain the anvil within the primer cup and therefore require only a simple cavity in the casing head to receive the primer cup. The cavity is easily cleaned and the cup readily removed with a suitable punch. The Boxer type primer is thus used in reloadable ammunition and, understandably, is preferred by avid competition shooters.
Accordingly, there is still a need for a sensitive, clean burning, efficient priming mix that is nontoxic to humans and can be used in Boxer type primers that are widely used in reloadable cartridges today.